1. Field of the Invention
The invention relates to a seat device, more particularly to a seat device for a bicycle.
2. Description of the Related Art
Referring to FIG. 1, a conventional seat device 1 includes a rigid casing 11, a cushion portion 12 formed on top of the casing 11, a supporting frame 13 mounted on a bottom face of the casing 11, and a fastening unit 14 for fastening the supporting frame 13 to the casing 11. The casing 11 converges from a rear portion 113 to a front portion 112, and includes a positioning piece 114 formed on the bottom face thereof proximate to the front portion 112, and two insert seats 115 formed on the bottom face thereof proximate to the rear portion 113. The supporting frame 13 includes a bent front section 131 inserted within the positioning piece 114, and two diverging arm sections 132 inserted respectively into the insert seats 115. The fastening unit 14 includes a cover plate 141 covering the front section 131 of the supporting frame 13, and a pair of screws 142 that extend through the cover plate 141 and that engage threadedly the positioning piece 114 so as to fix the supporting frame 13 to the casing 11.
Although the aforementioned conventional seat device 1 can achieve its intended purpose, the casing 11 has to be preformed with the positioning piece 114 and the insert seats 115, and has to be processed with insert holes and screw holes, so that formation of the casing 11 is complicated. Further, fixing the supporting frame 13 to the casing 11 is also complicated because the supporting frame 13 first has to be positioned on the casing 11 prior to being fastened to the casing 11 by the fastening unit 14.